code: def test_coco_instance():
      # use valid only, loading training split is very slow
      val = COCOInstanceTiny()
      name = str(val)
      assert len(val.classes) > 0
  
      for _ in range(10):
          index = np.random.randint(0, len(val))
          _ = val[index]
  
file_path: gluon-cv/tests/unittests/test_data_datasets.py
imports: from __future__ import print_function
  from __future__ import division
  import os
  import mxnet
  import numpy
  import gluoncv
  from gluoncv import data
  from .tiny_datasets import COCODetectionTiny, COCOInstanceTiny, VOCDetectionTiny, VOCSegmentationTiny
  import os.path
  import unittest
label_desc: Use image node_id 3 for calling a global function with example usage: test_coco_instance() without return types